Pulley block



March 31, 1931. l c. A. JOHANSSON Pumm BLOCK Filed m 28 1929 2 Sheets-$heet 1 Much 31, 1931. c. A. JOHANSSON PULLEY BLOCK Filed llay 28, 1929 2 Shook-Sheet 2' Patented Mar. 31, 1931 UNl'lD STATES CARL ALFRED JOHANSSON,

or nnnirirnnaesnoena, NEAR osLo,

NORWAY I PULLEY BLOCK Application filed May 28, 1929, Serial No. 366,

The invention relates to a pulley block particularly suitable for use as a self-acting lifesaving apparatus in the event of fire. It is constructed so that a load applied to eitherof the two ends of the lowering line will be automatically lowered at a limited speed and as soon one load is removed from one end of the line the apparatus is ready for lowering another load on the other end of the line which has been lifted during the lowering of the first load. 7

Such pulley blocks are known per se.

The speed-regulating mechanism in such, known pulley locks consists of a pendulum coacting with a star wheel on the shaft in such a manner that the turning motion is dependent upon the oscillations of the pendulum. Thlaoretically the apparatus fulfills any requirement which may be made of such a device. However the construction is rather complicated and consequently expensive.

The apparatus must be made very accurate if it is to actin the desired manner; the rattling noise is unpleasant to the person lowering and after a rather short time of use the wearing may cause the regulating wheel to stick so that the lowering is interrupted.

The purpose of the invention is now to avoid these inconveniences.

According to this inventio is pivoted at its lower upper end the pulley and a starwheel integral therewith. The starwheel coaets with a rigid gliiide the lower face of which is concentric with the pivot of the pendulum and the teeth of the star-wheel are formed so that the surfaces of the same alternately take up a position along the guide face. In order that a turning motion of the starwheel may be pos- U sihle the guide is provided with a recess in which the teeth may be turned when the starwheel is carried to the end of its oscillations.

The invention is illustrated in the accompanying drawings in which Fig. 1 shows in 5 a sectional view a preferred form of the same. ertical sectional view of the n the pendulum end and carries at its Fig. 2 is a v we at right angles to Fig. 1. Figs. 3 and t are diagrammatic vertical 'ews showing two different posisectional v1 tions of the movable parts of the block.

740, and in Great Britain September 28, 1928.

The block consists of side-parts 1 and anupp The block is connected of which the device.

or connecting part 2. to a hook 3, by means may be fastened to a suitable support. In the frame 1, 2 is pivoted, bymeans of a pin 4, a pendulum 5. upper edge 6 of th centricall rigid guide 7 which i s. also concentric with the pin 4. In the pen dulum is supported, by means ofa pin 8, a pulley 9 integral with a starwheel 10. The teeth of the starwheel coact witha rigid guide 11 having a lower guide face 12 concentric with the a recess 13. The teeth of the starwheel are, as appears from the drawing, formed in accordance with theface 12. The pendulum further is provided withtwo guide rolls l4, 15 for eachpart of the line 16. The contact of the line around the pulley 9 is secured by placing. the same on the inner side of the upper rolls 14 and the outerside of the lower rolls 15. i

The position shown fixed position, but on tion. a If the right ha in Figure 1 is not a ly an intermediate posind line part 16 is loaded, the parts will first take the position shown in Figure '3 wherein theright hand side of the star wheel tooth 6 located in recess 13 is in contact with the recess side. WVhen the line 16 "is pulled downwardly as indicated by the arrow with a suflicient force, the star wheel lO'tends to rotate clockwise, but because of the contact'at 8 no simple rotation can take place. The oonta press, upon the guide form the recess'13 and begin to slide at s. This can occur only by the tooth t pushing the whole wheel and pendulum back to the left (counter-clockwise) about the stationary pin l. During this motion the tooth tip t is slidingat 8 gradually downwardly from the position'shown in F igure' 3int0 the position shown in Figure 4: (the star wheel during such 1 motion turning a somewhat clockwise). When the tooth tip has reached the posi tionshown inFigure 14, itisabout to leave the recess 13 and this occurs upon a further slight'rotationofthe star wheel. Thereby the tip it will be free of the recess and slip ed by one side of cting tooth a will a frame having two pin 4 and in this even act under the guide 12. At the same time, the tooth 25 will enter into contact with the guide 12 at the left hand side. The tooth t is now within the recess and by the pull on the line 16 the whole pendulum.will suddenly rock clockwise about the pin 4, so as to put the tooth t in contact with the right hand side of recess 13, the parts resuming the position shown in Figure 3. Consequently the pendulum will rock to and fro (two strokes) each time anew tooth enters recess 13, as will be understood.

W hen the load on the right part of the line has been lowered the left part may be loaded and the right part lifted. The device will described above.

It will be understood that the details may be modified without departing from the scope of the invention.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In a pulley block, dulum pivoted to the frame at its lower end, a pulley supported in the same, a starwheel integral with the pulley, means for guiding the starwheel and turning the same, and meansfor keeping a line in contact with the pulley.

, 2. In a pulley block, a rigid frame, a pendulum pivoted to the frame at its lower end, a guide at its upper end concentric with the pivot and coacting with a rigid guide, a pulley supported by the pendulum, a starwheel integral with the pulley, means for guiding the starwheel and turning the same and means for keeping a line in contact with the pulley.

3. In a pulley block, a rigid frame, a pendulum pivoted to the frame at its lower end, having a guide at its upper end concentric with the pivot and coacting with a rigid guide, a pulley supported by the pendulum, a starwheel integral with the pulley, a further rigid guide concentric with the pivot of the pendulum, a recess in the latter guide, the teeth of thestarwheel being curved in accordance with the latter guide, and means for keeping a line in l. In a pulley block, dulum pivoted to the frame at its lower end, having a guide at its upperend concentric with the pivot and coacting with a rigid guide, a pulley supported by the pendulum, a starwheel integral with the pulley, a further rigid guide, concentric with the pivot of the pendulum, a recess in the latter guide, the teeth of the starwheel being curved in accordance with the latter guide and a number of line guide rollers supportedturnably in the pendulum and arranged in contact with the pulley. CARL ALFRED JOHANSSON.

quite in the same manner as a rigid frame, a pencontact with the pulley. a rigid frame, a pen- 7 so as to keep a line 

